The motors are a year old. I mean it is possible I guess corrosion and I'm not sure about the ground sharing but yes they share a fuel tank but I have normal fuel pressure

Check and clean the caps, what could it hurt? I clean mine twice a year and always find some corrosion.

Do you have marine or auto distributors?

Also you never answered- Did yoiu confirm no spark when the engines would not run? Fuel spark and compression, it is all you need. And i doubt you have an intermitten compression problem.

Next time it does it check for power to the purple wire on the coil, power to msd, and actual spark with a noid light on cyl one. If you have ignition it has to be a fuel issue.

Also make sure the power to the MSD is not coming from the same wire as the coil. In high KV ignition situations such as cold wet starts the coil and MSD combined will overload the power wire and cause voltage drop. Don't ask how I know

Sorry. Yes it's a no spark issue. Now that purple wire you speak of I have not checked yet. Work was busy. First thing tomorrow I will rip into it

They are auto distributors

Thanks for the help